Conventional mattresses have large flat, generally uniform surfaces. When a person sleeps on his or her side, the person's shoulder typically becomes compressed under the body or becomes bent forward or backward. Moreover, when sleeping on one's side, a person's backbone becomes significantly laterally curved. These various positions can be very uncomfortable and can cause serious pain and can even damage joints and nerves.
Conventional mattresses also present problems for couples trying to lie on a mattress while embracing with both sets of their arms. In addition to enduring the compressed arms, the embracing couple must also endure the discomfort in the shoulder or rib area of lying on the other person's arm.